20.500.12556/DiRROS-21377 Collision milling of oil shale ash as constituent pretreatment in concrete 3D printing Concrete is an essential construction material, and infrastructures, such as bridges, tunnels, and power plants, consume large quantities of it. Future infrastructure demands and sustainability issues necessitate the adoption of non-conventional supplementary cementitious materials (SCMs). At the same time, global labor shortages are compelling the conservative construction sector to implement autonomous and digital fabrication methods, such as 3D printing. This paper thus investigates the feasibility of using oil shale ash (OSA) as an SCM in concrete suitable for 3D printing, and collision milling is examined as a possible ash pretreatment. OSA from four different sources was collected and analyzed for its physical, chemical, and mineralogical composition. Concrete formulations containing ash were tested for mechanical performance, and the two best-performing formulations were assessed for printability. It was found that ash extracted from flue gases by the novel integrated desulfurizer has the greatest potential as an SCM due to globular particles that contain β-calcium silicate. The 56-day compression strength of concrete containing this type of ash is ~60 MPa, the same as in the reference composition. Overall, collision milling is effective in reducing the size of particles larger than 10 μm but does not seem beneficial for ash extracted from flue gasses. However, milling bottom ash may unlock its potential as an SCM, with the optimal milling frequency being ~100 Hz. digital concrete 3D printing oil shale ash supplementary cementitious material collision milling digitalni beton 3D tisk pepel iz oljnega skrilavca nadomestni cementni material kolizijsko mletje true false true MDPI AG Angleški jezik Slovenski jezik © 2025 by the authors. Licensee MDPI, Basel, Switzerland. Neznano 2025-01-30 06:57:36 2025-01-30 07:18:49 2025-01-31 03:37:11 0000-00-00 00:00:00 2025 0 0 This article belongs to the Special Issue Innovative Solutions for Concrete Applications str. 1-24 iss. 1, [article no.] 18 Vol. 10 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2025-01-13 620.1/.2 2412-3811 10.3390/infrastructures10010018 223542787 https://www.mdpi.com/2412-3811/10/1/18 1 1d2cca36-decf-11ef-ba3f-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=30441 RAZ_Hanzic_Lucija_2025.pdf RAZ_Hanzic_Lucija_2025.pdf 1 40A5247E683D6EAAB71C6F423EEEF5FB 74e53572c20a30459aa0becdfe1e2c899035451b75db0935e6b0a8dade3f7027 016b4f2e-ded2-11ef-ba3f-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=30442 https://doi.org/10.17605/OSF.IO/MWF9N 0 0e4358a6-ded2-11ef-ba3f-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=30443 Zavod za gradbeništvo Slovenije 0 0 0